1. Field of the Invention
This invention relates to a video signal processing circuit, and in particular, relates to a circuit by means of which an audio signal is injected into one or more line-scanning periods of the video signal as a time-compressed, buried audio signal.
2. Brief Description of the Prior Art
In conventional television systems, such as the NTSC system, in conventional television receivers, and in conventional video recorders, the audio signal and the video signal are processed separately. As a result, the bandwidth required for the television signal must be sufficient to accommodate both the audio signal and the video signal.
However, in a conventional video signal, there are provided between eight and twelve unused horizontal, or line-scanning periods occurring during the vertical blanking portion of each field period. Although any one such line-scanning period is sufficient to contain all of the audio information required for a given field period, it has heretofore not been possible to inject the audio signal into the unused line-scanning periods, and to later recover the audio signal from such line-scanning periods.